ABSTRACT
Abstract: Recent statements from the Brazilian federal government indicate that impacting economic activities, particularly commercial shrimp farming, are being encouraged in mangrove areas in the near future. Alterations of the National Action Plan and legal instruments that partially protected mangrove ecosystems have created an even weaker legal framework than previously existed. Such changes are leading Brazil far from the global call to conserve mangroves and from the Aichi targets and United Nations Sustainable Development Goals. Unfortunately, the loss of mangrove ecosystems and their ecosystem services will negatively impact living standards for Brazilians in coastal areas.
Resumo: As recentes determinações do governo Brasileiro indicam que atividades econômicas impactantes para os manguezais, particularmente a carcinocultura, serão incentivadas num futuro próximo. Alterações no Plano de Ação Nacional e em outros instrumentos legais, que parcialmente protegiam os manguezais, fragilizaram ainda mais os meios legais para proteção dessas áreas. Essas mudanças fazem o Brasil seguir na contra-mão da demanda global pela conservação dos manguezais e dos objetivos de desenvolvimento sustentável traçados pela Organização das Nações Unidas, bem como das metas de Aichi para a biodiversidade. Consequentemente, a iminente perda dos ecossistemas de manguezais impactará negativamente o padrão de vida dos Brasileiros que vivem em áreas costeiras.
ABSTRACT
El aumento de las emisiones de Gases de Efecto Invernadero (GEI) derivadas de las actividades humanas, son consideradas el principal responsable del cambio climático actual y el sector ganadero es responsable del 18 % de las emisiones de GEI en CO2 equivalente. El pasto kikuyo puede optimizar tanto la captura como la fijación del carbono. El objetivo del trabajo fue identificar las existencias de carbono en el pasto kikuyo en sus diferentes compartimentos, biomasa aérea (BA) y biomasa radicular (BR), a 20 y 40 cm de profundidad del suelo, bajo los sistemas tradicional y silvopastoril en diferentes relieves. Se realizaron seis muestreos (M) sucesivos de acuerdo al sistema de pastoreo (tradicional y silvopastoril), la geoforma del terreno (flanco cóncavo (FCC), flanco convexo (FCX), flanco rectilíneo (FR) y relieve plano (RP)). Se muestrearon la biomasa aérea (BA) y de raíces (BR). El método estadístico utilizado fue un diseño en bloques incompletos aleatorizados, se evaluaron dos tratamientos (T) (T1: tradicional y T2: silvopastoril) con cuatro bloques (B) en cada uno (B1: FCC, B2: FCX, B3: FR, B4: RP). El trabajo se realizó entre junio 2016 y junio 2017 en San Pedro de los Milagros, Antioquia Colombia. Los resultados permitieron determinar que las raíces a 20 cm de profundidad, el colchón muerto y las hojas, fueron los compartimentos con mayores existencias de carbono (4.52, 3.58 y 1.9 ton de C ha-1 respectivamente). Se encontraron diferencias (P < 0.05) entre relieve plano y el relieve rectilíneo para la biomasa de hojas, y entre el relieve plano con los demás relieves evaluados para la variable raíces gruesas a 20 cm de profundidad. La biomasa producida por la planta es directamente proporcional al carbono incorporado. La biomasa radicular, tanto para raíces finas como gruesas, contribuye a capturar en promedio 2 820 y 655 kg ha-1 de carbono a 20 y 40 cm de profundidad respectivamente. El pasto kikuyo contribuye a mantener reservas de carbono en las praderas. Por la alta producción de biomasa radicular, de colchón y la alta capacidad de rebrote en condiciones adversas, se concluye que este pasto juega un papel importante en la disminución de GEI y la conservación de los suelos del trópico alto bajo sistemas de lechería especializada.
The increase of Greenhouse Gases (GHG) emissions derived from human activities are considered the main cause of current climate change and the livestock sector is responsible for 18 % of the GHG emissions in CO2 equivalent. Kikuyu grass can optimize both carbon capture and carbon fixation. The aim of this paper was to identify carbon stocks in the kikuyu grass in its different compartments, above-ground biomass (AB) and below-ground biomass (BB) at 20 and 40 cm soil depth, under the traditional and silvopastoral systems in different reliefs. Six successive samplings (M) were taken according to the grazing system (traditional and silvopastoral system), and the geoform of the terrain (concave flank (CCF), convex flank (CXF), rectilinear flank (RF) and flat relief (FR)). The above-ground biomass and below-ground biomass were sampled. The statistical method used was a design in incomplete randomized blocks, two treatments were evaluated (T) (T1: traditional system and T2: silvopastoral system) with four blocks (B) in each one (B1: CCF, B2: CXF, B3: RF, B4: FR). This experiment was done from June 2016 to June 2017 in San Pedro de los Milagros, Antioquia, Colombia. The results allowed to determine that the roots at 20 cm depth, the dead creeping stems, and the leaves were the compartments with the highest carbon stocks (4.52, 3.58 and 1.9 ton of C ha-1, respectively). Differences were found (P < 0.05) between flat and rectilinear relief for the biomass of leaves, and between the flat relief with the other reliefs evaluated for the variable thick roots at 20 cm depth. The biomass produced by the plant is directly proportional to the incorporated carbon. The root biomass, both fine and thick roots, contributes to capture on average 2 820 kg and 655 kg of carbon per hectare at of 20 and 40 cm depth respectively. Kikuyu grass contributes to keep carbon reserves in the grasslands. Due to the high production of below-ground biomass and creeping stems, and its high capacity of regrowth under adverse conditions, this grass plays an important role in the reduction of GHG and the conservation of high tropical soils under specialized dairy systems.
ABSTRACT
El objetivo fue comparar, en cuanto a productividad en materia seca y captura de carbono, entre un sistema silvopastoril y un sistema tradicional en cinco fincas ganaderas de piedemonte del departamento de Casanare. En el lote experimental de cada finca se sembró una mezcla de cuatro especies de pastos, de los cuales Brachiaria brizantha fue la especie que tuvo un desarrollo exitoso en las cinco fincas, y con la cual se analizó su productividad en materia seca y captura de carbono. A los cinco meses después de la renovación de pastos en los lotes experimentales se obtuvo una productividad en materia seca entre 6,3 y 14,9 tMS/ha, y encaptura de carbono entre 2,7 y 6,4 tCOT/ha; mientras que en los lotes tradicionales estuvo entre 4 y 5 tMS/ha, y en captura de carbono entre 1,7 y 2,9 tCOT/ha. A los 20 meses en los lotes experimentales se obtuvo una productividad en materia seca entre 12 y 13,7 tMS/ha, y en captura de carbono entre 4,1 y 4,5 tCOT/ha; mientras que en los lotes tradicionales estuvo entre 4,4 y 6,5 tMS/ha, y en captura de carbono entre 1,4 y 2,1 tCOT/ha. Esto indica que la renovación de praderas con pastos adecuados y el pastoreo de rotación favorecen la producción en materia seca y la captura de carbono...
The goal was to compare, in terms of dry matter productivity and carbon sequestration, asilvopastoral system with a traditional system in five foothill cattle farms in the Departmentof Casanare. A mixture of four species of grass was planted in the experimental plot of eachfarm, of which Brachiaria brizantha was the species that had a successful development in thefive farms, and whose dry matter and carbon sequestration productivity was analyzed. Fivemonths after pasture renovation in the experimental lots, a dry matter productivity between6.3 and 14.9 tMS/ha and carbon sequestration productivity between 2.7 and 6.4 tCOT/ha were obtained; in traditional lots, dry matter productivity was between 4 and 5 tMS/ha,while carbon sequestration productivity was between 1.7 and 2.9 tCOT/ha. At 20 months, dry matter productivity between 12 and 13.7 tMS/ha, and carbon sequestration productivitybetween 4.1 and 4.5 tCOT/ha were obtained in experimental lots, while in traditionallots, dry matter productivity was between 4.4 and 6.5 tMS/ha, while carbon sequestrationproductivity was between 1.4 and 2.1 tCOT/ha. This indicates that renewal of grasslandswith suitable pastures and rotational grazing favor dry matter and carbon sequestration production...
O objetivo foi comparar, com respeito à produtividade em matéria seca e captura de carbono,um sistema silvipastoril e um sistema tradicional em cinco fazendas de criação de gado nodepartamento de Casanare. No lote experimental de cada fazenda plantou-se uma misturade quatro espécies de pastos, dos quais Brachiaria brizantha foi a espécie que teve um desenvolvimentobem-sucedido nas cinco fazendas, e com a qual analisou-se sua produtividadeem matéria seca e captura de carbono. Cinco meses depois da renovação de pastos nos lotesexperimentais obteve-se uma produtividade em matéria seca entre 6,3 e 14,9 tMS/ha, e umacaptura de carbono entre 2,7 e 6,4 tCOT/ha; enquanto que nos lotes tradicionais esteveentre 4 e 5 tMS/ha, e uma captura de carbono entre 1,7 e 2,9 tCOT/ha. Aos 20 meses noslotes experimentais obteve-se uma produtividade em matéria seca entre 12 e 13,7 tMS/ha, eem captura de carbono entre 4,1 e 4,5 tCOT/ha; enquanto que nos lotes tradicionais esteveentre 4,4 e 6,5 tMS/ha, e uma captura de carbono entre 1,4 e 2,1 tCOT/ha. Isto indica quea renovação de pastos com variedades adequadas e o pastoreio de rotação favorecem a produçãode matéria seca e a captura de carbono...